Numerical investigation of the dynamics of linear spin ss fields on Kerr background I. Late time tails of spin s=±1,±2s = \pm 1, \pm 2 fields

The time evolution of linear fields of spin $s = \pm 1$ and $s = \pm 2$ on Kerr black hole spacetimes are investigated by solving the homogeneous Teukolsky equation numerically. The applied numerical setup is based on a combination of conformal compactification and the hyperbolic initial value problem. The evolved basic variables are expanded in terms of spin-weighted spherical harmonics which allows us to evaluate all the angular derivatives analytically, whereas the evolution of the expansion coefficients, in the time-radial section, is determined by applying the method of lines implemented in a fourth order accurate finite differencing stencil. Concerning the initialization, in all of our investigations single mode excitations---either static or purely dynamical type initial data---are applied. Within this setup the late time tail behavior is investigated. Due to the applied conformal compactification the asymptotic decay rates are determined at three characteristic locations---in the domain of outer communication, at the event horizon and at future null infinity---simultaneously. Recently introduced new type of `energy' and `angular momentum' balance relations are also applied in order to demonstrate the feasibility and robustness of the developed numerical schema, and also to verify the proper implementation of the underlying mathematical model.Comment: 38 pages, 5 figures, typos correcte

Classification of Hungarian medieval silver coins using x-ray fluorescent spectroscopy and multivariate data analysis

A set of silver coins from the collection of Déri Museum Debrecen (Hungary) was examined by X-ray fluorescent elemental analysis with the aim to assign the coins to different groups with the best possible precision based on the acquired chemical information and to build models, which arrange the coins according to their historical periods. Results: Principal component analysis, linear discriminant analysis, partial least squares discriminant analysis, classification and regression trees and multivariate curve resolution with alternating least squares were applied to reveal dominant pattern in the data and classify the coins into several groups. We also identified those chemical components, which are present in small percentages, but are useful for the classification of the coins. With the coins divided into two groups according to adequate historical periods, we have obtained a correct classification (76-78%) based on the chemical compositions. Conclusions: X-ray fluorescent elemental analysis together with multivariate data analysis methods is suitable to group medieval coins according to historical periods. Keywords: X-ray fluorescence spectroscopy, Multivariate techniques, Coin, Silver, Middle age

A glükokortikoidok hatását és metabolizmusát befolyásoló gén-polimorfizmusok patofiziológiai szerepének vizsgálata = Pathophysiological significance of gene polymorphisms affecting glucocorticoid action and metabolism

A HSD11B1 génen in silico kutatásainkkal azonosított 65 polimorfizmus közül - transzkripciós faktorok kötőhelyein elhelyezkedésük alapján - 12 polimorfizmust részletesen vizsgáltunk és meghatároztuk populáció-szintű gyakoriságukat. A vizsgált 12 polimorfizmus közül a rs4844880 polimorf allél bizonyult kiemelten jelentősnek; a polimorfizmus hordozása kedvezőbb csont ásványianyag tartalommal (BMC) társult és jelenléte esetén Cushing-szindrómás betegekben magasabb szérum kortizol és osteokalcin koncentrációkat detektáltunk. Kimutattuk, hogy a polimorf allélt tartalmazó vektorral transzfektált Hela sejtek csökkent luciferáz aktivitást mutattak, ami magyarázza a rs4844880 allél hordozás csontanyagcserére kifejtett kedvező hatását. A GR gén 4 polimorfizmusának (Bcl1, N363S, ER22/23EK és A3669G) vizsgálatával kimutattuk, hogy a Bcl1 polimorfizmus jelenléte csökkent BMC értékkel társul Cushing-szindrómás betegekben. Kimutattuk továbbá, hogy várandós nőkben a Bcl1 polimorfizmus hordozása kockázati tényező a HELLP szindróma kialakulásában, és az ER22/23EK polimorfizmus jelenléte várandós nőkben csökkenti a graviditás alatti testsúly növekedés kockázatát. Mindezek az eredmények új adatokkal egészítik ki a glükokortikoidok iránti érzékenység pathofiziológiai jelentőségét, melyet nagyrészt genetikai tényezők, köztük elsősorban a HSD11B1 és GR gének variánsai határoznak meg. | Of the 65 polymorphisms identified in the HSD11B1 gene using our in silico analysis, 12 were further investigated based on their critical locations in sites which bind transcription factors, and their allelic frequencies were determined in healthy subjects. Of these 12 polymorphic alleles, the rs4844880 proved to be particularly important, because this polymorphic allele was associated with better bone mineral content (BMC) and, in patients with Cushing’s syndrome, with higher serum cortisol and osteocalcin concentrations. Hela cells transfected with this polymorphic variant showed decreased luciferase activity compared to those transfected with the wild-type variant, thus explaining the beneficial effect of the rs4844880 polymorphism on bone metabolism. Studies on the 4 polymorphisms of the GR gene (Bcl1, N363S, ER22/23EK and A3669G) indicated that the polymorphic Bcl1 allele was associated with a lower bone mineral content in patients with Cushing’s syndrome. In addition, we showed that the presence of this allele is a risk factor for HELLP syndrome in pregnant women, and that carriers of the ER22/23/EK polymorphism have a lower risk for weight gain during pregnancy. All these finding provide novel data on the pathophysiologic significance of glucocorticoid sensitivity, determined by genetic factors mainly including the HSD11B1 and GR gene variants

Is it possible to construct asymptotically flat initial data using the evolutionary forms of the constraints?

Near-Kerr black hole initial datasets are constructed by applying either the parabolic-hyperbolic or the algebraic-hyperbolic form of the constraints. In both cases, strongly and weakly asymptotically flat initial datasets with desirable falloff rates are produced by controlling only the monopole part of one of the freely specifiable variables. The viability of the applied method is verified by numerically integrating the evolutionary forms of the constraint equations in the case of various near-Kerr configurations.Comment: 43 pages, 6 figure

Consistency of QSAR models: Correct split of training and test sets, ranking of models and performance parameters

<div><p>Recent implementations of QSAR modelling software provide the user with numerous models and a wealth of information. In this work, we provide some guidance on how one should interpret the results of QSAR modelling, compare and assess the resulting models, and select the best and most consistent ones. Two QSAR datasets are applied as case studies for the comparison of model performance parameters and model selection methods. We demonstrate the capabilities of sum of ranking differences (SRD) in model selection and ranking, and identify the best performance indicators and models. While the exchange of the original training and (external) test sets does not affect the ranking of performance parameters, it provides improved models in certain cases (despite the lower number of molecules in the training set). Performance parameters for external validation are substantially separated from the other merits in SRD analyses, highlighting their value in data fusion.</p></div